亚临界水的特性及其技术应用

亚临界水技术因其绿色、无污染、成本低等特点,日益受到科研工作者的关注。亚临界水为在100℃到374℃之间,在外加压力的条件下仍然保持液态的水。亚临界水具有特殊的理化性质,如随温度的升高介电常数降低,离子积升高。本文对亚临界水的概念及其特殊性质进行了详细的阐述,同时对亚临界水技术现阶段的主要应用进行了总结,其主要被应用于农副产品中的有用成分及土壤中有害成分的提取、亚临界液相色谱和亚临界水中的化学反应。      

亚临界水萃取技术及其在食品方面的应用

介绍了亚临界水萃取的原理、装置、影响因素并对其近几年在食品方面的应用进行了综述.     

亚临界水萃取技术及其在食品方面的应用

介绍了亚临界水萃取的原理、装置、影响因素并对其近几年在食品方面的应用进行了综述。      

亚临界水提取技术在有效利用食品副产物中的应用

当水在374.2℃和22.1MPa (约218个大气压) 以上的高温、高压条件下,可形成既非液体又非气体第四状态,即所谓"超临界状态".在此状态下的水称为"超临界水".在稍微低于此温度和压力下的水称为"亚临界水".超临界和亚临界水都具有强烈溶解有机物和强烈分解能力等特性,利用此特性来提取有机物和有用成分,包括提取随分解反应产生的分解物是很有意义的.为高效率提取有关动、植物原料的有效成分和低分子化成分提供了酸碱法提取法达不到的新方法.新方法解决了诸如麦杆、豆腐渣和树叶等各种废弃物利用的难题,其意义重大.     

亚临界水萃取技术及其在肉品检测中的应用

介绍了近十几年发展起来的亚临界水萃取技术,包括亚临界水萃取的原理、装置、影响因素等;与其它的提取方法进行比较,结果表明亚临界萃取技术快速、方便、无有机溶剂残留,是一种绿色环保型萃取技术;最后对其近几年在肉品检测方面的应用进行了综述。     

亚临界水萃取麦胚蛋白及其功能特性的研究

以小麦胚芽为原料,通过单因素和响应面分析实验对亚临界水萃取麦胚蛋白的工艺条件进行优化,并对其功能特性进行评价。结果表明,麦胚蛋白最佳提取条件为:萃取温度130℃,萃取时间15 min,料水比1∶20 g/m L,p H为9.4。在此条件下,麦胚蛋白的提取得率达42.25%,乳化活性为113.63 m~2/g,乳化稳定性为82.16%,起泡性为71.45%,起泡稳定性为36.05%,持水性为4.21%,持油性为4.49%,溶解度为60.93%。与传统碱溶酸沉法相比,亚临界水萃取麦胚蛋白在提取时间、提取率等方面均具有明显优势。      

亚临界水萃取技术在植物精油提取中的应用潜力

植物天然精油含有多种活性成分,在医药、食品、烟用、化妆品等行业有着广泛的应用。亚临界水萃取技术作为一种新型的绿色萃取技术,越来越受到国内外研究者的关注,将其应用于植物精油的提取,对精油品质的提升具有重要意义。文中介绍了亚临界水萃取技术的原理、影响萃取效果的因素以及在植物精油萃取中的应用,对亚临界水在植物精油提取方面的应用进行了潜力分析和应用展望。     

亚临界水萃取技术在食品工业中的应用

本文综述了萃取温度、萃取压力、萃取时间、夹带剂对亚临界水萃取效果的影响及其在食品工业、农残检测前处理、植物精油提取的研究进展。最后对其在食品工业方面的应用前景进行展望。     

亚临界水萃取技术及其在生态纺织品检测中的应用初探

本文对近十几年发展起来的亚临界水萃取技术的研究进行了综述,介绍了亚临界水萃取技术的原理、影响因素及后续处理联用技术等.与其他传统的萃取方法相比,亚临界水萃取可以不使用或减少使用有机溶剂,是一种绿色环保型萃取技术,且方法具有较高的选择性,因此在环境、食品等领域的有机污染物检测中得到了广泛应用.本文将亚临界水萃取与旋涡混合液液微萃取相结合应用于纺织品中氯苯的测定,初步证明了方法在生态纺织品检测领域应用的可行性,为改进传统萃取检测技术提供参考.     

亚临界水萃取马兰挥发油及其抑菌活性的研究

以马兰挥发油提取得率为指标,通过单因素和正交试验,考察亚临界水萃取马兰挥发油的最佳实验条件,优选出马兰挥发油的亚临界水萃取工艺参数,并对马兰挥发油的抑菌活性进行研究。结果表明,当提取压力为5.0 MPa、提取温度160℃、水料比20∶1(mL/g)、提取时间30 min时,马兰挥发油提取得率达0.50%,与水蒸气蒸馏法和乙醚索氏提取法(挥发油提取得率分别为0.34%,0.23%)相比,亚临界水萃取马兰挥发油从时间和提取率上均具有明显的优势,而且马兰挥发油在一定浓度范围内对大肠杆菌、金黄色葡萄球菌、酵母菌均有较强的抑制作用。     

亚临界丁烷萃取芝麻油工艺及其品质分析研究

以脱皮芝麻冷榨饼为原料,采用亚临界丁烷萃取芝麻油。以芝麻油萃取率为考察指标,通过单因素实验和正交实验优化得到最佳萃取工艺条件为:萃取温度60℃,萃取次数6次,萃取时间30 min,料液比1∶3.0;在此条件下芝麻油萃取率达98.57%。所得芝麻油品质好,质量指标达到国家一级成品芝麻油标准。所得芝麻粕色泽浅,粗蛋白含量达49.08%,氮溶解指数为14.02%,是很好的植物蛋白资源。     

南瓜的功能特性及其在食品工业中的应用

从营养价值和药用价值两方面阐述了南瓜的功能特性 ,并介绍了南瓜脯、南瓜酱、南瓜粉及南瓜系列饮料等主要南瓜制品的工艺流程和操作要点。     

Subcritical water extraction of phytochemicals from Phlomis umbrosa Turcz

Subcritical water extraction (SWE) avoids the use of organic solvents when extracting active compounds. The SWE of phytochemicals from Phlomis umbrosa Turcz (PT) and the effect of antioxidant activity were investigated while varying the extraction temperature (from 100 °C to 200 °C) and time (from 5 to 25 min). The maximum yields of total polyphenols (142.02 ± 5.67 mg/g PT, mean ± SD) and flavonoids (33.69 ± 3.01 mg/g PT) were obtained for an extraction temperature and time of 200 °C and 20 min, respectively. The correlation of antioxidant activities in terms of their total phenolics and flavonoids contents suggest that the ABTS⁺ assay better reflects the antioxidant contents in SWE from PT than does the DPPH assay for extraction temperatures from 110 °C to 200 °C. At higher temperatures around 200 °C, SWE extracts affect the antioxidant activity due to the presence of not only flavonoids but also nonflavonoid phenolic compounds including prenylated flavonoids.Industrial relevanceThis study used subcritical water extraction (SWE) for the practical applications of the SWE process that extracts antioxidant compounds from medicinal herb such as Phlomis umbrosa Turcz. SWE is excellent technology to selectively extract bioactive compounds using temperature-dependent dielectric constant properties of water. As the temperature of water is increased, the polarity of water decreases. That's why it is selective extraction. The use of SWE in the present study was associated with high efficiency and antioxidant activities. These results indicate that SWE is an efficient and rapid method for extracting phytochemicals, and a safer product only using purified water. SWE has a potential to develop a commercial process for the extraction of phytochemicals. This method can be easily implemented on an industrial scale.     

Subcritical water extraction of phenolic compounds from potato peel

Potato peel, a waste generated from potato processing, is a disposal problem. But, potato peel is a good source of functional ingredients such as phenolic compounds. This study investigated the extraction of eight phenolic compounds (Gallic acid, GAC; Chlorogenic acid, CGA; Caffeic acid, CFA; Protocatechuic acid, PCA; Syringic acid, SGA; p-hydroxyl benzoic acid, PBA; Ferulic acid, FRA and Coumaric acid, CMA) from potato peel using subcritical water.Experiments were performed in a batch stainless steel reactor at 6 MPa, 2 mL/min and temperatures ranging from 100 to 240 °C at residence time of 30 to 120 min. High recoveries of phenolic compounds (81.83 mg/100 g; wet basis wb) were obtained at 180 °C and extraction time of 30 min compared to 3 h extraction with methanol (46.59 mg/100 g wb). CGA (14.59 mg/100 g wb) and GAC (29.56 mg/100 g wb) were the main phenolic compounds obtained from potato peel at 180 °C. Subcritical water at 160 to 180 °C, 6 MPa and 60 min might be a good substitute to organic solvents such as methanol and ethanol to obtain phenolic compounds from potato peel.     

PLA纤维:新的产业用途

API(Applied Polymer Innovations)研究所是一家研发聚合物高端用途的独立性研究机构.其利用在Akzo Nobel和Diolen工业纤维公司所积累的十多年经验,并在产业伙伴的紧密配合下,研发了PLA纤维新的用途,在此举出几个例子.     

Subcritical water extraction of flavonol quercetin from onion skin

Subcritical water could be an excellent alternative to organic solvent as a medium for extracting flavonol quercetin, due to its temperature-dependent selectivity, safety, efficiency of recovery, and lower cost. This study investigated the application of subcritical water extraction (SWE) of quercetin from onion skin and evaluated the effect of key operation conditions by varying the temperature (100-190 °C), extraction time (5-30 min), and mixture ratio of onion skin and diatomaceous earth (DE) (0.5:3.5-2:2) under high pressure (90-131 bar). The maximum yield of quercetin (16.29 ± 0.75 mg/g onion skin) was obtained at extraction temperature of 165 °C, extraction time of 15 min, mixture ratio of 1.5:2.5 for onion skin and DE. The SWE was compared with three conventional extraction methods in terms of the efficiency. The quercetin yield by SWE was over eight-, six-, and fourfold greater than those obtained using the ethanol, methanol, and water-at-boiling-point extraction methods, respectively.     

可食性大豆蛋白膜的性能及应用前景

介绍了大豆分离蛋白（SPI）膜的特性及各种强化方法：热处理和碱处理,交联作用,多组分复合,物理处理对SPI膜的影响,提出了SPI膜的应用前景。     

南瓜籽油亚临界流体萃取工艺及成分研究

采用亚临界流体技术萃取南瓜籽油,在单因素试验基础上通过正交试验对工艺条件进行优化,并对此法所得南瓜籽油的脂肪酸组成及理化性质进行分析。结果表明:最优萃取工艺条件为萃取次数4次、料液比1∶5、萃取温度30℃、萃取时间25 min,在此条件下得到南瓜籽提油率为89.12%;所得南瓜籽油共检测出5种脂肪酸,主要为棕榈酸(18.84%)、亚油酸(40.17%)、油酸(29.38%)、硬脂酸(10.67%)和花生酸(0.93%);其理化指标为碘值(I)124.5 g/100 g、酸值(KOH)1.6 mg/g、皂化值(KOH)188.5 mg/g、相对密度0.915。